Questions - Transmitter Theory

Question file 19


  1. Morse code is usually transmitted by radio as:             STUDY NOTES 
    1. an interrupted carrier
    2. a voice modulated carrier                                QUESTIONS WITH ANSWERS 
    3. a continuous carrier
    4. a series of clicks
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  2. To obtain high frequency stability in a transmitter, the VFO should be:
    1. run from a non-regulated AC supply
    2. in a plastic box
    3. powered from a regulated DC supply
    4. able to change frequency with temperature
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  3. SSB transmissions:
    1. occupy about twice the bandwidth of AM transmissions
    2. contain more information than AM transmissions
    3. occupy about half the bandwidth of AM transmissions
    4. are compatible with FM transmissions
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  4. The purpose of a balanced modulator in a SSB transmitter is to:
    1. make sure that the carrier and both sidebands are in phase
    2. make sure that the carrier and both sidebands are 180 degrees out of phase
    3. ensure that the percentage of modulation is kept constant
    4. suppress the carrier while producing two sidebands
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  5. Several stations advise that your FM simplex transmission in the "two metre" band is distorted. The cause might be that:
    1. the transmitter modulation deviation is too high
    2. your antenna is too low
    3. the transmitter has become unsynchronised
    4. your transmitter frequency split is incorrect
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  6. The driver stage of a transmitter is located:
    1. before the power amplifier
    2. between oscillator and buffer
    3. with the frequency multiplier
    4. after the output low-pass filter circuit
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  7. The purpose of the final amplifier in a transmitter is to:
    1. increase the frequency of a signal
    2. isolate the multiplier and later stages
    3. produce a stable radio frequency
    4. increase the power fed to the antenna
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  8. The difference between DC input power and RF power output of a transmitter RF amplifier:
    1. radiates from the antenna
    2. is dissipated as heat
    3. is lost in the feedline
    4. is due to oscillating current
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  9. The process of modulation allows:
    1. information to be impressed on to a carrier
    2. information to be removed from a carrier
    3. voice and Morse code to be combined
    4. none of these
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  10. The output power rating of a linear amplifier in a SSB transmitter is specified by the:
    1. peak DC input power
    2. mean AC input power
    3. peak envelope power
    4. unmodulated carrier power
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